Su Jinyuan, Yan Yu, Song Jia, Li Junqing, Mao Jianfeng, Wang Nian, Wang Wenting, Du Fang K
The College of Forestry, Beijing Forestry University, Beijing, China.
College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.
Front Plant Sci. 2018 Oct 31;9:1571. doi: 10.3389/fpls.2018.01571. eCollection 2018.
Forestland fragmentation caused by overexploitation of forest resources can in principle reduce genetic diversity, limit gene flow and eventually lead to species developing strong genetic structure. However, the genetic consequences of recent anthropogenic fragmentation of tree species remain unclear. , which has extremely small populations distributed mainly in Changbai Mt. in Northeast (NE) China, has recently endured severe habitat fragmentation. Here, we investigate the pattern of genetic diversity and structure, identify risk factors, predict the future distribution and finally provide guidelines for the conservation and management of this species. We used three chloroplast and two mitochondrial DNA fragments, which are both paternally inherited in yews but differ in mutation rates, to genotype a total of 265 individuals from 26 populations covering the distribution of the species in China. Both chloroplast and mitochondrial data showed high degrees of genetic diversity, extensive gene flow over the entire geographical range and historical stability of both effective population size and distribution of the species. However, ecological niche modeling suggests a decrease in suitable areas for this species by the years 2050 and 2070. The maintenance of high genetic diversity and the existence of sufficient gene flow suggest that recent fragmentation has not affected the genetic composition of the long-lived tree . However, severe impacts of anthropogenic activities are already threatening the species. Conservation and management strategies should be implemented in order to protect the remnant populations.
森林资源的过度开发导致的林地破碎化原则上会降低遗传多样性、限制基因流动，并最终导致物种形成强大的遗传结构。然而，近期人为导致的树种破碎化的遗传后果仍不明确。，其种群数量极少，主要分布在中国东北的长白山，最近经历了严重的栖息地破碎化。在此，我们调查遗传多样性和结构模式，识别风险因素，预测未来分布，并最终为该物种的保护和管理提供指导方针。我们使用了三个叶绿体和两个线粒体DNA片段，这些片段在红豆杉中都是父系遗传的，但突变率不同，对来自26个种群的总共265个个体进行基因分型，这些种群覆盖了该物种在中国的分布范围。叶绿体和线粒体数据均显示出高度的遗传多样性、在整个地理范围内广泛的基因流动以及该物种有效种群大小和分布的历史稳定性。然而，生态位建模表明，到2050年和2070年，该物种的适宜面积将减少。高遗传多样性的维持和充足基因流动的存在表明，近期的破碎化并未影响这种长寿树种的遗传组成。然而，人为活动的严重影响已经在威胁该物种。应实施保护和管理策略以保护残余种群。
